A rapid and efficient method for static aeroelastic analysis of a flexible slender wing when considering the structural geometric nonlinearity has been developed in this paper. non-planar vortex lattice herein is used to compute aerodynamics wings with large deformation. The finite element introduced nonlinear statics analysis. surface spline structure/aerodynamics coupling. characteristics wind tunnel model are studied by presented, also evaluated comparing results those obtained from two...

This paper describes a method proposed for modeling large deflection of aircraft in nonlinear aeroelastic analysis by developing reduced order model (ROM). The is applied solving the static and trim problems flexible containing geometric nonlinearities; meanwhile, non-planar effects aerodynamics follower force effect have been considered. ROMs are computational inexpensive mathematical representations compared to traditional finite element (FEM) especially solutions. approach structure...

The complicated flow conditions and massive design parameters bring two main difficulties to the aerodynamic optimization of axial compressors: expensive evaluations numerous variables. To address these challenges, this paper establishes a novel fast platform for compressors, consisting radial basic function (RBF)-based blade parameterization method, data-driven differential evolution optimizer, computational fluid dynamic (CFD) solver. As versatile interpolation RBF is used as shape...

The intercooling recuperated cycle (ICR) is commonly employed in marine gas turbines to enhance thermal efficiency. However, the addition of an intercooler may lead increased dimension and structural complexity ICR turbines. To address this issue, we propose improved configuration intermediate pressure compressor – axial-centrifugal combined (ACC) with high inlet hub-tip ratio flow rate. aerodynamic performance ACC at multi-operating points optimized via free-form deformation method for...

VFAs (very flexible aircraft) have begun to attract significant attention because of their good flight performances and application potentials; however, they also bring some challenges researchers due unusual lightweight designs large elastic deformations. A framework for the geometrically nonlinear aeroelastic stability analysis very wings is constructed in this paper illustrate unique characteristics convenient use these engineering analysis. The model includes structure finite elements...

Abstract The sense of discomfort when watching stereoscopic display caused by visual fatigue has hindered the widespread applications display. In this work, we explore relationship between and parallax using subjective assessment. subjects is evaluated after viewing different samples. It shows that exacerbates greater in negative than positive parallax. Surprisingly, results indicate can be alleviated with tiny parallax, which increases comfort perception. We envision able to provide helpful...

The active magnetic compensation coil is of great significance for extensive applications, such as fundamental physics, aerospace engineering, national defense industry, and biological science. shielding demand increasing over past few decades, better performances the are required. To maintain normal operating conditions some sensors, coils often used to implement near-zero field environments. Many design methods have been developed different fields. It opportune review development...

The stability and bifurcation of a flexible 3D rotor system are investigated in this paper. is discretized by elements reduced using component mode synthesis. Periodic motions margins obtained the shooting method path-following technique, local periodic determined Floquet theory. Comparisons indicate that 1D systems have general resemblance characteristics while mass eccentricity rotating speed changed. For both systems, orbit size has same order magnitude, vibration response identical...

Portals placement in a large virtual scene can help users improve navigation efficiency, but determining the number and positions of portals has some challenges. In this paper, we proposed two automatic methods for efficient VR navigation. To reduce reverse redirections, also real-time portal orientation determination algorithm. For any given single-floor outdoor scene, our automatically place portals.

The stability and bifurcation of a flexible rod-fastening rotor bearing system with transverse open crack in fastening rod are investigated. nonlinear dynamic model cracked is established based on the finite element method. A methodology introduced where shooting method, path-following technique, Floquet theory combined for determining periodic solutions margins system. effects depth mass eccentricities studied by numerical simulations. Results show will reduce due to presence crack, two...

VTOL (Vertical Takeoff and Landing) highspeed flight are important performance requirements of fixed-wing UAV (Unmanned Aerial Vehicles) high-speed helicopters. In this paper, a distributed ducted fan propulsion configuration is proposed based on electric technology. Aiming at the demand quick aerodynamic calculation in aircraft conceptual design kind configuration, analysis method equivalent actuator disk single model proposed. The characteristics analyzed, conversion corridor given....

The nonlinear dynamic effects of the misalignment between inner disks in a flawed–machining rod–disk rotor is studied. Non–uniform stress distribution due to obtained based on 3D static solution. concomitant unbalances, including constant mass eccentricity and speed–variant bending, are taken into account dynamics. results show that bending leads stability reduction vibration growth. There distinctive feature rotor’s goes up again after critical speed. maximum allowable according its...

Abstract The aerodynamic design and performance improvement of compressors in gas turbine development, especially multistage axial flow with numerous parameters, pose challenges relying on manual experience. To address computational inefficiency optimization turbomachinery, an platform is developed based the Direct Free-Form Deformation (DFFD) method. This method, offering full-geometry three-dimensional parameterization arbitrary degrees freedom, conducts direct manipulation control vertex...

Abstract In this paper, a large generator rotor with complex clearance is taken as the research object, and dynamic analysis model of established. This study focuses on prediction contact stiffness its widely distributed interface cross-scale interstitial rotor. Furthermore, characteristics torsional under typical state are studied, combined tested verified. Through theoretical experimental study, influence mechanism revealed.

Abstract A high-load mixed-flow compressor with an extremely high inlet hub/tip ratio (0.889) is designed and analyzed for replacing the rear stages of a multistage pressure axial compressor. The effects blade number, splitter blades dimensionless geometric parameters on impeller performance are investigated by improved loss model. full-surface parameterization control method adopted optimizations tandem stator. As retrofit design compressor, unconventional type axial-co-mixed-flow combined...

Rotor and stator rubbing is a common fault of rotating machinery, for instance, aircraft engine, currently, numerous methods are presented to address the issues Rub-impact fault. For purpose effective research different diagnosis methods, experimental system Rub-Impact achieved in this paper, with mixed programming Matlab VC++ applied. As an illustration, three such as Linear-SVM, RBF-SVM BP network, embedded respective results analyzed. In addition, brief introduction Visual C ++ MatLAB...

To make the rotation of rotor blade more accurate, elastic deformation in system is considered this paper. Firstly, number and direction generalized coordinates are determined by freedom degree finite element method Lagrange equation used to build dynamical system. Then, mass matrix other coefficient obtained according principle flexible multibody dynamics. Finally, violation correction get numerical solution simulation. Additionally, angular displacement end with y-direction z-direction...

In this paper, a nonlinear damage compensation scheme of adaptive variable step size digital back propagation (DBP) algorithm is proposed, which based on the particle swarm optimization (PSO) to iteratively compute coefficient and influence factor at same time. This improves capability DBP improved by 2.3% compared with traditional DBP.